Organism

Thresholds for the detection (at p = 0.67 correct) of the direction of discrete linear movements in the horizontal plane, having a cosine bell velocity trajectory and duration of 3 s, were determined in 24 subjects. Thresholds in the Z body axis (mean 0.154 m X s-2) were significantly higher than thresholds for movement in the X (mean 0.063 m X s-2) and Y… (More)

BACKGROUND
A recent experiment demonstrated that low frequency linear oscillation through the Z-axis of the body was more nauseogenic when applied in the vertical direction, with subjects seated upright, than in the horizontal direction, with subjects supine.
HYPOTHESIS
The nauseogenicity of low frequency linear oscillatory motion is dependent on… (More)

Cadaveric lumbar intervertebral joints were subjected to physiologic loads to simulate flexion. The resistance to bending was measured first with the joint intact and again after cutting in turn through the supraspinous/interspinous ligaments, the ligamentum flavum, and the capsular ligaments of the apophyseal joints. In this way the part played by each of… (More)

The aim of this study was to determine whether the time course of recovery of tolerance, as assessed objectively by rechallenge with motion, paralleled the subjective recovery from motion sickness. Subjects (n = 20) were exposed to 5 pairs of nauseogenic motion challenges in which the time interval between the end of the first and the start of the second of… (More)

1. The 5-hydroxytryptamine (5-HT3) receptor antagonist, GR 38032F, which possesses potent anti-emetic properties in vomiting induced by cancer chemotherapeutic drugs, has been tested to determine its value in the prophylaxis of motion sickness induced by cross-coupled stimulation. The double-blind trial compared GR 38032F with both a placebo (lactose) and… (More)

We investigated whether linear whole-body acceleration along the interaural y-axis influenced the concurrent perception of visual motion direction as has been shown for angular accelerations. A sled running on air bearings along a 7.5-m track was used to accelerate 18 subjects at two different linear accelerations. These young, healthy volunteers, aged… (More)

Values for the compressive breaking load of lumbar vertebrae at physiological strain rates show enormous scatter across the population, ranging from 0.8 kN to nearly 16 kN. Increase in strength was found at faster strain rates, but differences in compressive strength between upper and lower lumbar vertebrae were not significant. Hydraulic strengthening does… (More)

On the ground, the essential requirement to remain orientated is a largely unconscious activity. In flight, orientation requires a conscious effort by the pilot particularly when the visual environment becomes degraded and a deceptive force environment becomes the frame of reference. Furthermore, an unusual force environment can determine the apparent… (More)

The aim of this study was to determine whether varying the predetermined malaise level at which provocative motion challenges were stopped would affect the habituation rate. At the rate of 2 per day, 21 motion challenges were delivered, stopping either at initial symptoms or at moderate nausea, on a cross-over design randomized between subjects (n = 20).… (More)